Let me start by saying that I did not use these in the 'recommended' way..

I was having an issue in the trigger of my A5. If I held the trigger down as I cocked the gun, the slider would stick to the sear and would not reset as I eased the trigger out. This was causing my gun to cock, but not fire. I would have to wiggle the trigger in order to unstick the slider from the sear and reset the slider underneath the sear, making the trigger ready to raise and trip the sear for the next firing cycle. (If you know how your trigger works you will understand what I'm saying.)

I tried using different springs in the sear, different springs in the slider, going back to the stock trigger, flipping the slider upside down, hell I even oiled the slider and the sear to try and get them to slip off of each other. Nothing worked. I thought my A5 was F**ked. It then occurred to me - maybe if I can make the pin holding up the sear bigger, this would make the sear sit too high up for the slider to catch on..

I went out and asked the tech if he thought my hair brained scheme would work. He responded 'Dude, I don't even know how that's happening.' So I bought the Hair trigger kit, lined up a pin to hold my sear about a millimeter above the metal slider on the trigger and presto! She worked!

Conclusion:

I don't know how these things are supposed to be used and I don't care. These things saved my A5! If you have a sticky trigger, these could be what bring it back to life. I think $25 is a little steep for the amount of material you get but for providing pretty much the only aftermarket pins for your trigger, It's worth it if you need them.

8 - They saved my A5. If you have a sticky trigger, they might just save yours too! I'm just a little peeved about the price...

-EDIT- I tried using these to actually shorten the trigger pull for my a5 RT. Using the most enlarged pin under the sear, I manager to get the pull to basically nothing. HOWEVER, when I did this, 1 in every 20 shots or so fired halfway through the previous cycle, meaning the cyclone couldn't keep up. Maybe if I got a QEV the cyclone could keep up, but for the moment, I just went down a couple pin sizes. Still very happy and maintaining the rating at 8 as per review body.

EDIT 2 - My Tippy started doing full auto burps on me the other day. Turns out that when you lower the sear, you catch the hammer with less of the sear. This wears your sear down faster than normal. The accelerated wear had caused my sear to miss catching the hammer, causing the gun to burp. I raised the sear almost back to factory levels and bought a new one just in case. Everything is back to working order but it gave me a bit of a fright!

So I had to use a new sear. Even taking out the hairpin trigger kit, my old sear had somehow worn so badly it was virtually useless. Lowering the score on the hairpin trigger kit from an 8 to a 6 - Yes, it works, but it is reeeaaallllyy hard on your gun internals. Wears them out at least twice as fast..

Technically this product does do what it says, it reduces your trigger pull. Unfortunately this product isn't plug-and-play though. You can't just put 2 pins in and start using it. You have to test it hundreds of times just to get the correct configuration. Then when you got it right, you have to test it out on the field.

--- More detailed explanation ---
The product works by replacing 2 pins inside your trigger assembly. You have a choice of 5 different pins with varying (all larger than standard) sizes. The larger the size, the shorter your pull (simplified). The size you need varies from marker to marker. Even if your friend is using the exact same model marker, his might need a different pin size than yours.

So your sitting at home, testing out each pin configuration. When suddenly you found it, the perfect pin size. You pack up your stuff and wait for the day you get to use it. You get to the field and start playing. You bump into something, then try to fire! Your marker just goes full-auto because your trigger won't reset. Yep, something you didn't account for. Something not even stated in the instructions. If you were too aggressive with it, a slight bump in the marker kicks you out of the game.

Conclusion:

After trying to work this thing, I've decided not to use it at all. The benefits are too small for its weaknesses. I can't afford to be kicked out of a game because of it. That and Tippmann markers are known for its durability. Yet, this product actually reduces to the lifespan of the trigger assembly. The larger pins causes more rubbing to occur which increases wear and tear.

When I first got the hairpin kit I was using a stock trigger on the A-5. It greatly improved the amount of shots I could put out per second, by reducing the distance of the trigger pull, and allowing me to trip the sear a little easier because of the aggressive pitch of the sear caused by the pins.

When I purchased an E-Grip I could tell that the pins greatly reduced the amount of pull that was required to make the grip cycle. The pins also help conserve battery power, due to the fact that the sear is much easier to trip

Conclusion:

So worth it! If you have a stock trigger and want to up the rate of fire that you can put out, or even if you have an E-grip, or a response, these pins are so worth it, they help increase your efficiency and rate of fire. They are worth the money